We're dividing 840621 by 51 
We want to figure out the number of times 840621 can be divided by 51.

Advancing to step 1:
8 divided by 51 is 0 with a remainder of 8.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we take 0 away from 8, we end up with 8.
Take the next digit (4) from the dividend and append it to 8, then repeat: 84 / 51

On to step 2:
51 can be fit into 84 1 times, resulting in a remainder of 33.
Write down 1 as next digit of the result. 
Result so far: 1.0
If we take 51 away from 84, we end up with 33.
Append the next digit (0) from the dividend to 33 and continue with: 330 / 51

Advancing to step 3:
When dividing 330 by 51, we get 6 with a remainder of 24.
The number 6 becomes the next digit in our result. 
Result so far: 16.0
If we subtract 306 from 330, we get 24.
Include the next digit (6) from the dividend after 24, then repeat: 246 / 51

Step 4:
51 can be fit into 246 4 times, resulting in a remainder of 42.
Record the quotient 4 as the next digit in the result. 
Result so far: 164.0
The remainder is 42 after subtracting 204 from 246.
Append the next digit (2) from the dividend to 42 and continue with: 422 / 51

Advancing to step 5:
When dividing 422 by 51, we get 8 with a remainder of 14.
The next digit of our result is 8. 
Result so far: 1648.0
Subtract 408 from 422 to get 14.
Grab the next digit (1) from the dividend, add it to 14, then carry on: 141 / 51

Moving on to step 6:
51 goes into 141 2 times with a remainder of 39.
Put 2 as the next digit of the answer. 
Result so far: 16482.0
Deduct 102 from 141 and we're left with 39.
Since there are no more digits in the dividend, we add a zero to the remainder making it 390, and continue the process.

Advancing to step 7:
51 goes into 390 7 times with a remainder of 33.
Put 7 as the next digit of the answer. 
Result so far: 16482.7
The remainder is 33 after subtracting 357 from 390.
Since there are no more digits in the dividend, we add a zero to the remainder making it 330, and continue the process.

Step 8:
When dividing 330 by 51, we get 6 with a remainder of 24.
Record the quotient 6 as the next digit in the result. 
Result so far: 16482.76
If we take 306 away from 330, we end up with 24.
Since there are no more digits in the dividend, we add a zero to the remainder making it 240, and continue the process.

Going ahead to step 9:
51 can be fit into 240 4 times, resulting in a remainder of 36.
The next digit of our result is 4. 
Result so far: 16482.764
The remainder is 36 after subtracting 204 from 240.
Since there are no more digits in the dividend, we add a zero to the remainder making it 360, and continue the process.

Let's proceed to step 10:
360 divided by 51 is 7 with a remainder of 3.
Put 7 as the next digit of the answer. 
Result so far: 16482.7647
Subtracting 357 from 360 leaves us with 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

Advancing to step 11:
51 goes into 30 0 times with a remainder of 30.
Record the quotient 0 as the next digit in the result. 
Result so far: 16482.7647
Subtracting 0 from 30 leaves us with 30.
Since there are no more digits in the dividend, we add a zero to the remainder making it 300, and continue the process.

Let's proceed to step 12:
The number 51 fits into 300 5 times, leaving a remainder of 45.
Write down 5 as next digit of the result. 
Result so far: 16482.764705
Deduct 255 from 300 and we're left with 45.
Since there are no more digits in the dividend, we add a zero to the remainder making it 450, and continue the process.

Let's proceed to step 13:
The number 51 fits into 450 8 times, leaving a remainder of 42.
Write down 8 as next digit of the result. 
Result so far: 16482.7647058
Deduct 408 from 450 and we're left with 42.
Since there are no more digits in the dividend, we add a zero to the remainder making it 420, and continue the process.

On to step 14:
420 divided by 51 is 8 with a remainder of 12.
The number 8 becomes the next digit in our result. 
Result so far: 16482.76470588
Deduct 408 from 420 and we're left with 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

In conclusion, the division gives 16482.76470588 with a balance of 1.2e-08.